title: Sporadic Legionnaires' disease: the role of domestic electric hot-water tanks.
abstract: Sporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated with Legionella spp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the same Legionella isolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study. Legionella was recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.
authors.affiliation: Department of Microbiology - Infectious Diseases, Hôpital Maisonneuve-Rosemont, 5415 L'Assomption Boulevard, Montreal, Quebec, Canada.
authors.forename: S F
authors.initials: SF
authors.lastname: Dufresne
authors.forename: M C
authors.initials: MC
authors.lastname: Locas
authors.forename: A
authors.initials: A
authors.lastname: Duchesne
authors.forename: C
authors.initials: C
authors.lastname: Restieri
authors.forename: J
authors.initials: J
authors.lastname: Ismaïl
authors.forename: B
authors.initials: B
authors.lastname: Lefebvre
authors.forename: A C
authors.initials: AC
authors.lastname: Labbé
authors.forename: R
authors.initials: R
authors.lastname: Dion
authors.forename: M
authors.initials: M
authors.lastname: Plante
authors.forename: M
authors.initials: M
authors.lastname: Laverdière
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D060766:Drinking Water / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D016952:Legionella pneumophila / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007877:Legionnaires' Disease / Q000453:epidemiology / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011792:Quebec / Q000453:epidemiology; D012621:Seasons; D013696:Temperature; D014881:Water Supply / Q000706:statistics & numerical data*
chemical_list: D060766:Drinking Water